Attrtion-mill.



E. P. ALSTED.

v ATTRITION MILL. APPLICATION mp0 SEPT. 12. we.

nmmmFwumma ATTURNQYE a ppq e yi said axis. The inner endsli) of saidpor tions of said ribs are comparatively narrow and diverge outwardly to a greater degree than radially to provide-a shearing cutofthe line of engagement which travels .1nwardly as shown in Fig. 7 of the dranfing. The ribs dicatedb'y'the numeral-20th form sharper cutting edges and which cutting edges .Wlll remain in better cutting shape during the wear otsaidribs, p

The radial ribs 11 liaveqtheir cuttin edges 21:91.1 their opposite sides substantial y parallel with relation to each other and tangentially with relation to a small circle 'c0ncentric to the .axis ,of-the plates and Whose diameter approximately equals the width o1 the tribs toform ,a slight shearing cut, the line of engagement 01 which travels outwardly. The'ribs 11 increase in width to Ward-the base-of the plates as indicated by the numeral 22 to reinforce and increase the strength of the ribs so that they can better -\yvithstand engagement with particles of metal or other foreign matter which may inadvertentlyget in the grain being reduced. The, foreign matter thus engaged will be cut or broken into such small particles by the relnforced ribs that no damagewil 1 be .don tojfthe miter radial ribs of less strength. The inner side edge 26 of the eceentricf ribs; I14: "and 14H bevels inwardly toward the axis of the plates to also reinforce these,.-ribs for. the sa ine purpose jiist before imentioned. V v .t r The material being reduced between the.

attrition faces ofjthe plates is ted to said plates. {from the inner portion thereof; and is moved outwardly therefromby centrifngal .f 'C-,:Z", v; t. ltW-ill-bd noticed, that the eccentrlc r1bs' 14 c ;01- -1 r of the'segmental plates extend in a cnrve of larger diameter than that portion ofitheplateuPoniwhiCh the rib-is positioned, org-{in otheigwords the rihcis eccentric to the pathof ear plates-are assembled onathe disks or heads oli the' attrition ,milljthe'; ends? of the eccentricuribsmeet -and' form a hexagonal; shaped ;rib'.; with,-cor11ers i.23 and "curved .sides- 524.- The-hexagon;shapeghrib is positioned COIl'r-I centric tojthe axis of the disks and one of the ribs js of slightly larger diameter than 3 When?the opposing plates are h p h aa time other portions of the ribs will belspaced other radially-to form communi- ;oat1ng passageways as indicated a'by the;

from ea numeral: 25 in .F ig.-6,1to permit some at the material tofreelypass from the innerp'ocksalts be obtained,

12 are also underc it as in,

l. ofithje segment, and when the otated the corners jot-the smaller ribln lll overlap; the portionsof the larger rib and form a shearing cut and atTthesamd iii-gconcentric-with relationTIto t'.

B h sid sass rihea ia ribs' are in the opposite "direction and the same rell rom the foregoing description it will be seen that the attrition mill is of veryv sin ple construction and that the material be re" duced is spreadevenlytbctween the grin g plates and that the Wear thereof 'is thus evenly distriblited" th'roughmit 'allg'of tlie working portions of the plates;

.VlZhatI claim as my-invention is;

1. An attrition, mill, comprising --"rota-j table 'opposite.plates provided "with; radialribs, the material engaging-edgesof-Zthi i is of opposit plates being "undercut aiifd eanvcrging, toward; the axis ofsaid plates for a portion or; their length'jand b ats-para lel to each other at other portions-of their length to advance the line fof cutting-engagement of said ribs toward theperiphcry of the said platesior a'p'ortion- 'of the lengthier said ribs and toward the" axis of said plates along other portions of saidr'ibs. at T 2. An 'attriti'0'11 i-mill," comprisingrota; table opposite "plates provided W-ithra'd-i'alg and eccentric transverse ribs forming pool?"- ets :ther ebetween, the. vmaterial engaging edges of the radial i r'ibs" being; partly} 11'n'-' '95 '7 dercut and' converging toward the axis at said plates for a portion of their" lengthT'a-iid being- -.p arallcl .to' eaehothei at' othe'i fp'o'n tioii s rof'their ength' to *a'dyance' the line of cutting engagement of said ribs toward-the periphery of said plates for; a portion "of the length.- of-jsai'cl ribs and-toward thefaxis of" said plates along other portions of sairilf i ibs; portions of said radial ribsbein'g beveled to .7 ward the -plates to reinforce their side' ed'ge i105 portion's,-; said transverse ribs of opposite plates during rotation partly overlapping each "other to perroit' passa'ge oat-"material from pockets inclosediwithin the transverse rib to pockets; ontsi'd'e of said-rib;

a 3. grinding; late foif i attrition comprising a segmental} plate'providedgwith lengths then extendiiigfiin parall l t a certain'distanoe, and a beveled ri exten ing transversely across th'e' r d linecccentric to' tl 1e ofg-"sa" a; Atl'grindin'g plate: gfofr attritio comprising a\segmental plate havin v V and transve'rse iihs," onter portions of the'; radial ribs being undercut and the ater-ia'l 7 engaging edges- 0f sa'id' nndercnt "o converging toward eachoth axis of thef late fora portion andg parallel to each'iothen inner'aportions, said inner iparalleli p'o 10 beingbeveled,"the?- outer-i-transver "ibjb c iris 'ofwtf 0.3 A grlndm late forett r itionmills rialbeingjundereut and converging tpward 1: 0 i

cox npri'sing a segmental plate having-raj;- Ga Ch I O thGI I 1 e dial and transverse ribs, theinner eu tting In testimony whereof, I aflixmysign tu edge portions ofthe radial ribs being parj mfij 211161 and beveled to initially engage the ma- EDWARD P, ALSTED. 

